Improvement in dovetailing-machines



4 Sheets- Sheet 1. C. STBNGEL. Dovetailing-Machine. No. 2 11-,5-31.Patented Jan. 21,1879.

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G. S'IBNGEL. Dovetailing-Machine. A No. 211,531. Patented Jan. 21,1879.

llllllll'li!l UNITED' STATES PATENT FFICE.

CHARLES, STENGEL, OF HAMILTON, ASSIGNOR TO J. A. FAY & CO., OFCINCINNATI, OHIO.

IMPROVEMENT IN DOVETAILING-MACAHINES.

Specification forming part of Letters Patent No. 211,531, dated January21, 1879; application led November 22, 1878.

To all whom 'it mag/uconcem:

Be it known that I, CHARLES STENGEL, of

Hamilton, in the county of Butler and State of Ohio, have inventedcertain new and useful'Improvements in Dovetailing-Machines; and I doherebyl declare that the following is a full, clear, and exactdescription of the invention, which will enable others skilled in theart toV whichit appertains to make and use the same, reference being hadto the vaccompanyin g drawings, and to letters of reference markedthereon, which form a part of this specification.

, My invention relates to that class of machines which are adapted forforming dovetail joints in wood-work by means of rotary cutters, andmore especially to such machines as are constructed to automaticallyround one side of the dovetailed tenons on one of the two boards orpieces of lumber operated upon, so that said rounded side of the tenonsmay make a'close-fitting joint with the necessarilyrounded ends. of thedovetailed mortises in the other board or piece of lumber.

My invention consists in the construction and arrangement of devices forautomatically traversing the lumber-carriage across the rotary cutter;also, in so constructing the machine that joints may be formed duringboth the forward and backward movement of the carriage; also, in theconstruction and mounting of the cutter, and in the construction andcombination of other parts, as will be hereinafter more fully set forth,and pointed out specically in the claims.

In the annexed drawings, Figure 1 is a front elevation of adovetailing-machine embodying my invention. Fig. 2 is a rear elevationof the same. Fig. 3 is a transverse vertical section thereof on the linex, Fig. l. Figs. 4 to S are detail views of different parts' of themachine. Figs. 9 to 16 are detail views, showing the construction andmode of mounting of the cutter.

' Ihave illustrated my invention in connectionY with adovetailing-machine, which operates with a single rotary cutter, shown,forl instance,v in my United States Letters Patent rNo.1183,030. It isobvious, however, that my invention may be embodied in machines of y thecharacter shown in my United States Letters Patent No. 199,117, as wellas in other kinds of dovetailing-machines.

A represents the frame of my machine. B

is the lumber earriage, provided with the clamping-rollers :C C,operating on angle-plates C' C', for holding the two pieces of lumber tobe operated upon, one piece being held in a horizontal and the other ina vertical position. The carriage B is movable up and down in dovetailedguides on an intermediate traveling plate, 1),"and this traveling plateis movable horizontally upon suitable ways on a saddle, E, attached tothe main frame of the machine. Ihe carriage Bis provided with a slottedyoke, F, which may be adjusted up and down by means of a set-screw, a,or in any other suitable manner, for the purpose of regulating theup-and-down movement of the carriage. This yoke F is provided with afixed pin or guide, b, entering the vertical grooves x between the ribson the iixed plate G, said guide-pin fitting theV grooves so snugly thatit has no lateral play therein. The ribs x extend below the l'ower edgeof plate G, forming a comb. The vertical side of the lumber-carriage isprovided with the comb d, to allow the cutting-tool to pass throughbetween the teeth thereof into the lumber. The carriage is movedautomatically by the following means: Upon the traveling plate D isattached a bearing for the journal e of a worm-gear, H, whichf mesheswith a wormscrew, I, arranged in bearings back of and parallel with theplate E. The journal e is, at its forward end, provided with acrankpin,f, having a cam, h, on its end, which cam enters the slot y inthe yoke F of the lumbercarriage, while the crank-pin f at times entersbetween the ribs w of plate G, its throw being equal to the distancebetween two adjacent grooves,

The effect of this mechanism on the lumbercarriage is modified by theribbed plate Gr and the fixed guide-pin b on the yoke F, and theconjoined operation of all of this set of devices may be set forthbrielly thus: Take the position of the part-s shown in Fig. l, thecarriage having arrived at the lowest point of its descent, and,consequently, the cutting of two corresponding mortises having just beencompleted. The yoke F of the lumber-carriage rests on the flat side ofcam h, the crank-pin is below and free from the ribs while the guide-pinb of the yoke F is between two ribs, of plate G. Now, let the journal ebe turned in the direction of the arrow,(see Fig. 1,) cam h will at onceoperate on yoke F, and begin to elevate the carriage, whereby guide-pinb is also elevated. By the. time guide-pin l) reaches the upperextremity of the groove w, in which it travels for the time being,crank-pin f enters the next adjacent groove az. At this point of timethe carriage will have ascended so far as to have withdrawn the verticalpiece of lumber entirely and the horizontal piece of lumber partly fromrotary cutter W. As journal e continues to.

turn, its crank-pin f becomes engaged between the ribs of the groove acadjacent to the groove which guide-pin b is just leaving at the Lipperend, and a compound movement is now imparted to thelumber-carriage-namely, cam h continues to elevate it, while crank-pinf(which, in consequence of its engagement in the plate or rack G, causesa traversing or traveling motion of journal e) draws it in a horizontaldirection. The throw of crank pin f is exactly the same as the throw ofcam h, and the cam is so formed that this combined action of thecrank-pin and cam results in moving the lumber-carriage in the arc ofacircle, the center of which is in a plane midway between the groove,fr, just left by guide-pin b and the adjacent groove, between thedownwardly-projecting ribs w of which crank-pin f is operating. The axisof journal e is on the line of the lower ends of ribs so that thecrank-pin f makes one-half of a revolution from the time of enteringbetween to the time of escaping from any two ribs w. Hence, in movingthe lumber-carriage from groove to groove of plate G, the traverse ofany point of such carriage is semicircular, in consequence of which therotary cutter W will cut a semicircular rounding upon thev lower side ofthe horizontal piece of lumber in shifting the carriage from groove togroove. In other words, one side of the tenons of the horizontal pieceof lumber will be rounded to fit the rounded inner end of the mortisescut in the vertical piece of lumber.

In the lower part of the frame A is a hori- ,zontal shaft, J, to whichmotion is communicated by belt or otherwise from the line-shaft, andupon this shaft J are secured two beveled friction-gears, K K. Betweenthese frictiongears is a single friction-gear, L, secured upon a shaft,M, which has its bearings in a swinging or pivoted box, N, so that thegear L may be thrown in contact with either of the gears K and K', anddriven thereby alternately in one direction and the other. Upon theother end of the shaft M is a pulley, connected by belt O with a pulleyon the end ofthe screw I.

The pivoted box N is provided with an arm, which is connected by a rod,i, with the lower :end of the pivoted shipper-lever l?` for swinglumberand puts in two fresh pieces.

ing the box N. Below the plate E is arod, R, running parallel therewlth,and provided near each end with an adjustable collar or tappet, m. Thelever l? passes through an eye of a projection on the rod It, as shownfully in Fig. 6, and as the lever is moved one way or the other it movesthe rod, and vice versa. The shipper-lever also passes up through aloopon the frame, and is rmly clamped to the loopbar by a spring, n, withsufficient friction to overbalance lthe tendency of the friction-gears Kor K to move the friction-gear L out of frictional contact. when drivenby either of them.

Now, as ,the carriage moves to one end it strikes the tappet m, movingthe rod R and also the shipper-lever P, thereby disengaging thefriction, so as to stop the feed. The operator then removes the twofinished pieces of He then ships the lever P still farther than thelumbercarriage shipped it, so as to force gear L into v frictionalcontact with the other friction-gear on shaft J. This again starts theoperation of the machine, the traverse of the carriage being now in areverse direction, however. Ai'- ter rounding the last tenon thecarriage again stops the machine by striking the tappet on the other endof rod It, when fresh pieces are again put in and the feed reversedagain.

The carriage always stops at the extreme upward throw of the crank andat the extreme right or left hand end of the series of grooves a: ofplate or rack Gr.

By this construction of devices joints are formed both during theforward and the backward movement of the carriage, whereas in machinesof this character it has heretofore been necessary to return thecarriage by hand back to the starting-point, and joints could only beformed while the carriage was traveling in one direction.

From a pulley on the shaft Ja belt, S, connects with a pulley on themandrel V, which carries anddrives the bit or cutting-tool W. ThemandrelVis bored out eccentrically from the end to receive the shank Aof the cutter W, which shank is also turned eccentric to the end of thecutter; On account of this double eccentricity, the 'cutter can easilybe adj usted to cut larger or smaller, as desired, by simply turning thecutter in the mandrel, and the cutter is held in any position by aset-screw, 19,01' other suitable means.

Instead of having the hole in the mandrel bored eccentric, it may bebored concentric, and an eccentric thimble, B', inserted therein tomatch the eccentric shank ofthe cutter.

The use of a concentrically-bored mandrel provided with aneccentrically-bored thimble for the reception of theeccentrically-shanked cutter possesses several advantages over theeccentrically-b'ored mandrel. For instance,

this part of my invention can in that form be readily applied toexisting machines. Again, in case the mandrel were sprung by overstrainand required to be trued up in a lathe,

it could be much more easily centeredthan an eccentrically-boredmandrel. This feature of eccentricity of the cutter and mandrel-chuck isapplicable to routing and other cutting tools.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. In a dovetailing-machine, a lumber-carriage operating automaticallyup and down and backward and forward by means of a traveling crank andreversible feed device, whereby joints may be formed during both theforward and backward movement, the whole constructed substantially asherein set forth.

2. The combination, substantially as before set forth, of thelumber-carriage provided with a guide-pin, the rack for controlling themovements of the carriage, and the traveling connected cam and crank-pinfor moving the carriage.

3. The combination, substantially as before set forth, of thelumbercarriage provided with a guide-pin, the rack for controlling themovements of the carriage, the traveling connected cam and crank-pin formoving the carriage, and the reversible feed-gearing.

4. The combination of a mandrel having an eccentric tool-socket and acutting-tool provided with an eccentric shank, as herein set forth.

5. The combination of a concentrically-bored mandrel, aneccentric sleeveor thimble inserted therein, and a cutting-tool provided with aneccentric shank, substantially as herein set forth.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two witnesses.

CHARLES STENGEL.

Witnesses:

Jos. O. Novias, l GRAS. C. DAVIS.

